This invention relates to a gas insulating switchgear installed in an electrical station such as an electrical substation.
FIGS. 1 to 3 illustrate one example of a gas insulating switchgear which has been widely used heretofore and which is disclosed in Japanese Patent Laid-Open No. 60-187217.
This gas insulated switchgear is arranged to include an interrupter 1, bus side and line side disconnectors 2 and 3, grounded switches 4 and 5, and a transformer 8. These components are respectively contained within separate metallic vessels each filled with SF.sub.6 gas, and connected to another through insulating spacers 10.
As shown in FIG. 2, the interrupter 1 is positioned horizontally behind an operator unit 11 and a monitor panel 12 disposed in a side-by-side relationship. Above the interrupter 1, the bus side and the line side disconnectors 2 and 3 are respectively connected to first and second openings provided on the side surfaces of the vessels with operators 13 and 14 being respectively and directly mounted thereon. Also, the grounded switches 4 and 5 are each connected to one of the openings of the respective vessels with operators 15 and 16 being respectively and directly mounted thereon. Control cables of the operators 15 and 16 are wired by protective pipes, such as wiring tubes 17, through various routes which are concentrated at the monitor panel 12, to allow further connection to the external circuit. A ground pipe 18 provides the connection to ground. Both the disconnectors 2 and 3 and the grounded switches 4 and 5 are electrically insulated from the metallic vessels and electrically operated to be opened and closed.
Reference numeral 6 designates bus bars, reference numeral 7 designates cable heads and reference numeral 9 designates line side support.
The operation and function of the above-described conventional switchgear will now be described.
The operational forces for the movable contacts of the disconnectors 2 and 3 as well as the grounded switches 4 and 5 are transmitted through sealed shafts mounted to the outer walls of the metallic vessels.
On the other hand, as shown in FIG. 1, the operational force of each operator mounted to the side wall of the metallic vessel, such as the operator 13 for the bus bar side disconnector, is transmitted to and output from the sealed shaft by a suitable power source including manual power.
The operators 13 to 16 of the disconnectors 2 and 3 as well as the grounded switches 4 and 5 are provided with handle insertion openings 20 for receiving therein respective manual handles and open-and-close state indication windows 19 so that operational state display and the direct manual operation can be achieved. Within the operator unit 11 disposed in front of the interrupter 1, an operator for the interrupter is contained so that the operation of the interrupter can be achieved not only remotely but also manually or electrically. The display of the operating states of the interrupter can be visually confirmed from a front inspection corridor through the state indication window 19.
A simulation bus bar monitoring window 22 is provided in the monitor panel 12 to monitor the state of the overall system and various indicators for alarm displays such as gas leakage. Also, a monitoring instrument window 21 is disposed in the monitor panel 12 to allow visual monitor of the gas pressure or the like.
Since the conventional system is constructed as described above and a number of vessels are combined in a complex manner, the structure is complex, the overall dimension of the switchgear is increased and it requires large installation space.
Moreover, the displays of the operating states of the interrupter 1 and the overall switchgear system can be visually confirmed from a position facing the frontal view of the switchgear (the front inspection corridor), the open-and-close indication of the disconnectors and the grounded switches is difficult to confirm due to the sideways dispositions of the operators 13-16 and the corresponding indication windows 19. Therefore, it is often necessary to climb over the vessels or to squeeze through narrow passages between the vessels to reach the desired operator during the manual operation, inspection and maintenance of the switchgear. Also, since the vessels, the operators with indication windows and the control cables are provided or arranged in arbitrary arrangement and route, the overall system becomes complex and heavy, degrading operability, maintenance and inspectability. Further, the time required for stopgap or permanent repair upon unforeseen accidents in the system can be disadvantageously prolonged.